Coating system and method for coating interior fluid wetted surfaces of a component of a semiconductor substrate processing apparatus

ABSTRACT

A fluid handling component for a vacuum chamber of a semiconductor substrate processing apparatus is provided. The fluid handling component comprises interior fluid wetted surfaces and an atomic layer deposition (ALD) or molecular layer deposition (MLD) barrier coating on the interior fluid wetted surfaces wherein the fluid wetted surfaces which include the ALD or MLD barrier coating are configured to be contacted by a process gas and/or fluid during a semiconductor substrate processing process wherein the ALD or MLD barrier coating protects the underlying fluid wetted surfaces from erosion and/or corrosion.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Divisional of U.S. application Ser. No. 14/572,087filed on Dec. 16, 2014, which claims priority under 35 U.S.C. § 119(e)to U.S. Provisional Application No. 61/922,196, filed on Dec. 31, 2013,the entire content of which is incorporated herein by reference thereto.

FIELD OF THE INVENTION

This invention pertains to coatings formed by atomic layer depositionand molecular layer deposition, and may find particular use in coatinginterior fluid wetted surfaces of a fluid handling component for avacuum chamber of a semiconductor substrate processing apparatuses.

BACKGROUND

Semiconductor substrate processing apparatuses are used to processsemiconductor substrates by techniques including etching, physical vapordeposition (PVD), chemical vapor deposition (CVD), plasma enhancedchemical vapor deposition (PECVD), atomic layer deposition (ALD), plasmaenhanced atomic layer deposition (PEALD), pulsed deposition layer (PDL),molecular layer deposition (MLD), plasma enhanced pulsed depositionlayer (PEPDL) processing, and resist removal. Semiconductor substrateprocessing apparatuses, such as the aforementioned processingapparatuses, can comprise a plurality of interrelated, but discrete,fluid handling components that can be used to transform a group ofsemiconductor substrates from an unfinished state to a completed statewith applied microcircuitry. Such fluid handling components can includeinterior fluid wetted surfaces which are exposed to corrosive and/orerosive process gases. Accordingly, it is desirable that such interiorfluid wetted surfaces of such fluid handling components be resistant tocorrosion and/or erosion when exposed to respective process gases orprocess fluids.

SUMMARY

Disclosed herein is a coating system for forming an atomic layerdeposition (ALD) barrier coating or a molecular layer deposition (MLD)barrier coating on interior fluid wetted surfaces of a fluid handlingcomponent for a vacuum chamber of a semiconductor substrate processingapparatus. The interior fluid wetted surfaces between an inlet port andan outlet port of the fluid handling component wherein the interiorfluid wetted surfaces contact process fluid during processing of asemiconductor substrate in the vacuum chamber of the semiconductorsubstrate processing apparatus. The coating system includes the fluidhandling component, wherein the interior fluid wetted surfaces define aprocess region of the coating system. A gas supply system is in fluidcommunication with the process region of the fluid handling componentwherein the gas supply system supplies process gases to the processregion of the fluid handling component through the inlet port thereofsuch that an ALD or MLD barrier coating can be formed on the fluidwetted surfaces of the fluid handling component. An exhaust system is influid communication with the process region of the fluid handlingcomponent wherein the exhaust system exhausts the process gases from theprocess region of the fluid handling component through the outlet portthereof.

Also disclosed herein is a fluid handling component for a vacuum chamberof a semiconductor substrate processing apparatus. The fluid handlingcomponent comprises interior fluid wetted surfaces and an atomic layerdeposition (ALD) or molecular layer deposition (MLD) barrier coating onthe interior fluid wetted surfaces wherein the fluid wetted surfaceswhich include the ALD or MLD barrier coating are configured to becontacted by a process gas and/or fluid during a semiconductor substrateprocessing process wherein the ALD or MLD barrier coating protects theunderlying fluid wetted surfaces from erosion and/or corrosion.

Further disclosed herein is a method of forming an atomic layerdeposition (ALD) or molecular layer deposition (MLD) barrier coating oninterior fluid wetted surfaces of a fluid handling component for avacuum chamber of a semiconductor substrate processing apparatus whereinthe interior fluid wetted surfaces of the fluid handling component forma process region for forming the ALD or MLD barrier coating. The methodcomprises sequentially injecting atomic layer deposition gases ormolecular layer deposition gases into an inlet port of the fluidhandling component with a gas supply system and forming an ALD or MLDbarrier coating on the interior fluid wetted surfaces, and sequentiallyexhausting the atomic layer deposition gases or the molecular layerdeposition gases from an outlet port of the component with an exhaustsystem.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 illustrates an exemplary coating system according to embodimentsdisclosed herein.

FIG. 2 illustrates an exemplary coating system according to embodimentsdisclosed herein.

FIG. 3 illustrates an exemplary fluid handling component according toembodiments disclosed herein.

FIG. 4 illustrates an exemplary fluid handling component according toembodiments disclosed herein.

DETAILED DESCRIPTION

In the following detailed description, numerous specific embodiments areset forth in order to provide a thorough understanding of the apparatusand methods disclosed herein. However, as will be apparent to thoseskilled in the art, that the present embodiments may be practicedwithout these specific details or by using alternate elements orprocesses. In other instances, well-known processes, procedures, and/orcomponents have not been described in detail so as not to unnecessarilyobscure aspects of embodiments disclosed herein. As used herein the term“about” refers to ±10%.

Disclosed herein is a coating system (as used herein an ALD or MLDapparatus) for forming an atomic layer deposition (ALD) barrier coatingor a molecular layer deposition (MLD) barrier coating on interior fluidwetted surfaces of a fluid handling component for a vacuum chamber of asemiconductor substrate processing apparatus. The interior fluid wettedsurfaces between an inlet port and an outlet port of the fluid handlingcomponent wherein the interior fluid wetted surfaces contact processfluid during processing of a semiconductor substrate in the vacuumchamber of the semiconductor substrate processing apparatus. The coatingsystem includes the fluid handling component, wherein the interior fluidwetted surfaces define a process region of the coating system. A gassupply system is in fluid communication with the process region of thefluid handling component wherein the gas supply system supplies processgases to the process region of the fluid handling component through theinlet port thereof such that an ALD or MLD barrier coating can be formedon the fluid wetted surfaces of the fluid handling component. An exhaustsystem is in fluid communication with the process region of the fluidhandling component wherein the exhaust system exhausts the process gasesfrom the process region of the fluid handling component through theoutlet port thereof.

Semiconductor substrate processing apparatuses can comprise a pluralityof interrelated, but discrete, fluid handling components which can beupstream, downstream, or inside of the vacuum chamber of thesemiconductor substrate processing apparatus wherein the processingapparatus is used to process a semiconductor substrate supported in areactor space of the vacuum chamber. For example, such fluid handlingcomponents can include, but are not limited to, an exhaust assembly suchas disclosed in commonly-assigned U.S. Published Application No.2013/0248113, a gas delivery system such as disclosed incommonly-assigned U.S. Published Application No. 2013/0305190, a gas boxsuch as disclosed in commonly-assigned U.S. Pat. No. 6,101,419, a gasstick such as disclosed in commonly-assigned U.S. Published ApplicationNo. 2013/0056087 or U.S. Pat. No. 6,283,143, a proximity head such asdisclosed in commonly-assigned U.S. Pat. No. 7,363,727, aliquid-dispensing device (fluid delivery system) comprising an array ofliquid-dispensing nozzles such as disclosed in commonly-assigned U.S.Published Application No. 2013/233356, an air filtering unit and/orexhaust system such as disclosed in commonly-assigned U.S. Pat. No.8,282,698, a deionized water pressure system and corresponding facilitylines such as those disclosed in commonly-assigned U.S. Pat. No.6,406,273, a gas distribution system including a gas switching sectionsuch as disclosed in commonly-assigned U.S. Published Application No.2012/0070997, a temperature controlled member such as a temperaturecontrolled top plate disclosed in commonly-assigned U.S. Pat. No.7,517,803, or a temperature controlled base plate disclosed incommonly-assigned U.S. Pat. No. 7,939,784, and/or a diffuser such asdisclosed in commonly-assigned U.S. Pat. No. 6,663,025, all of which arehereby incorporated by reference in their entirety.

Such fluid handling components include interior fluid wetted surfacestherein wherein erosive and/or corrosive process gases and/or fluids cancause deterioration of the interior fluid wetted surfaces and/or causecontaminants from the interior fluid wetted surfaces to be released intothe vacuum chamber (i.e. processing environment or reactor space) of thesemiconductor substrate processing apparatus, thereby causing processingdefects and/or substrate contamination of a semiconductor substrateduring semiconductor substrate processing. For example, iron containingparts of fluid handling components at the upstream of a vacuum chamber(exposed to high-pressure corrosive gases) and at the downstream of thevacuum chamber (exposed to low-pressure gas and possibly radicals) cancause substrate contamination when erosive and/or corrosive processgases and/or liquids interact with the interior fluid wetted surfacesreleasing iron into the vacuum chamber, thus leading to ironcontamination of the semiconductor substrate being processed. Incontrast to components of vacuum chambers, which tend to have simplegeometry, iron containing components (contributing to substratecontamination) of downstream or upstream fluid handling components, arevery hard to be clearly identified, let alone fix. This is because thereare too many components included in the fluid handling components withirregular geometries and too many components included in the fluidhandling components which could degrade under high temperature coatingprocesses. For example, iron-free Si CVD coatings can requiretemperatures of about 400° C. to apply wherein components of fluidhandling components such as a spring-like diaphragm material (Co—Nialloys)/O-rings/plastic handles of a gas valve within a gas box (asillustrated in FIG. 3) could not survive at coating temperatures ofabout 400° C.

To alleviate contaminates from interior fluid wetted surfaces of fluidhandling components, whole upstream or downstream fluid handlingcomponents are pre-assembled, vacuum sealed, and configured to form aprocess space of an atomic layer deposition (ALD) apparatus or amolecular layer deposition (MLD) apparatus wherein ALD or MLD barriercoatings can be formed on the interior fluid wetted surfaces of thefluid handling components. FIG. 1 illustrates an embodiment of a coatingsystem for forming an ALD or MLD barrier coating on interior fluidwetted surfaces of a fluid handling component. To form the ALD or MLDbarrier coating on the interior fluid wetted surfaces of a fluidhandling component 110, ALD or MLD coating gases are injected from anALD or MLD precursor gas delivery system 100 (gas supply system) throughan inlet port 105 of the fluid handling component 110 and exhaustedthrough an outlet port 115 of the fluid handling component 110 by anexhaust system 120. The fluid handling component is then removed fromthe auxiliary ALD precursor gas delivery system 100 and the exhaustsystem 120. When disconnected from the gas delivery system and theexhaust system, the whole fluid handling component, having an ALD or MLDbarrier coating on the interior fluid wetted surfaces thereof can beinstalled upstream, downstream, or in a vacuum chamber of asemiconductor substrate processing apparatus wherein the ALD or MLDbarrier coating of the fluid handling component will reducecontamination, such as metal contamination, therefrom.

The method of forming the ALD or MLD barrier coating on interior fluidwetted surfaces of the fluid handling component includes sequentiallyinjecting atomic layer deposition gases or molecular layer depositiongases into an inlet port 105 of the fluid handling component 110 withthe gas supply system 100 thereby forming an ALD or MLD barrier coatingon the interior fluid wetted surfaces of the fluid handling component100 and sequentially exhausting the atomic layer deposition gases or themolecular layer deposition gas from an outlet port 115 of the component110 with an exhaust system wherein the interior fluid wetted surfaces ofthe fluid handling component form a process region for forming the ALDor MLD barrier coating. For example, the method can include injecting apulse of a first reactant gas on the interior fluid wetted surfaces ofthe fluid handling component, and injecting a pulse of a second reactantgas on the interior fluid wetted surfaces of the fluid handlingcomponent to react with the first reactant gas to form a layer of theALD or MLD barrier coating on the interior fluid wetted surfaces of thefluid handling component wherein the method preferably includesrepeating each injection step a plurality of times. The method alsoincludes exhausting excess first reactant gas with the exhaust systemafter injecting the pulse of the first reactant gas, and exhaustingexcess second reactant gas and reaction byproduct(s) with the exhaustsystem after dispensing the pulse of the second reactant gas. Preferablythe first and second reactant gases are injected into the fluid handlingcomponent forming layers of the ALD or MLD barrier coating on theinterior fluid wetted surfaces of the fluid handling component until thecoating is formed to a desired thickness.

In a preferred embodiment, the method includes injecting a pulse of afirst reactant gas on the interior fluid wetted surfaces of the fluidhandling component, and then injecting a first pulse of purging gas onthe interior fluid wetted surfaces of the fluid handling component topurge excess first reactant gas from interior fluid wetted surfaces andthe fluid handling component. The method includes injecting a pulse of asecond reactant gas on the interior fluid wetted surfaces of the fluidhandling component to react with the first reactant gas to form a layerof the ALD or MLD barrier coating on the interior fluid wetted surfacesof the fluid handling component, and injecting a second pulse of purginggas on the interior fluid wetted surfaces of the fluid handlingcomponent to remove excess second reactant gas and reaction byproduct(s)from the interior fluid wetted surfaces and the fluid handlingcomponent. The method also preferably includes exhausting excess firstreactant gas with the exhaust system after injecting the pulse of thefirst reactant gas, exhausting excess first pulse of purging gas withthe exhaust system after injecting the first pulse of the purging gas,exhausting excess second reactant gas and reaction byproduct(s) with theexhaust system after dispensing the pulse of the second reactant gas,and exhausting excess second pulse purging gas with the exhaust systemafter injecting the second pulse of the purging gas.

Coatings deposited by an ALD or MLD process tend to have higher purityand better conformality to microfeature topography than analogous filmsdeposited via CVD. In addition, ALD and/or MLD processes are oftencarried out a lower temperature than CVD processes to deposit analogousmaterials, thereby reducing thermal stresses on individual componentswhich make up the fluid handling component having the interior fluidwetted surfaces. For example, an Al₂O₃ ALD coating can be applied attemperatures as low as about 50° C. (typical range is about 50° C. to300° C.). In alternate embodiments, ALD or MLD coatings can be formed atabout room temperature. This enables the coating of all of the interiorfluid wetted surfaces of the fluid handling component without “frying”components included in the fluid handling component such as O-rings,MFCs, gaskets, and/or valves. In an embodiment, the fluid handlingcomponent 110 can be disposed in an oven (not shown) such that thetemperature of the interior fluid wetted surfaces of the fluid handlingcomponent 110 can be increased to a desired temperature such that theALD or MLD barrier coating process can be performed. In a preferredembodiment, one or more heaters 150 can be arranged to be in thermalcontact with the fluid handling component 110 such that the one or moreheaters 150 can increase the temperature of the interior fluid wettedsurfaces of the fluid handling component 110 to a desired temperature.The one or more heaters 150 can be, for example, a heater (i.e. a heatertape) which includes resistance wire therein wherein the heater isdisposed on a surface of the fluid handling component 110, a heatinglamp arranged to heat the fluid handling component 110, or the like.

In a preferred embodiment, multiple fluid handling components which eachinclude interior fluid wetted surfaces are in fluid communication witheach other such that the interior of each fluid handling component formsthe process region of the ALD or MLD apparatus (i.e. coating system). Inthis manner, an ALD or MLD barrier coating can be formed on interiorfluid wetted surfaces of each fluid handling component at the same time.For example, to form an ALD or MLD barrier coating on the interior fluidwetted surfaces of a first fluid handling component 110 a and a secondfluid handling component 110 b, ALD coating gases are injected from anALD or MLD precursor gas delivery system 100 (gas supply system) throughan inlet port 105 of the first fluid handling component 110 a andexhausted through an outlet port 115 of the second fluid handlingcomponent 110 b by an exhaust system 120 wherein the first fluidhandling component 110 a and the second fluid handling component 110 bare in fluid communication with one another, as illustrated in FIG. 2.The fluid handling components 110 a, 110 b can then be removed from thegas supply system 100 and the exhaust system 120 wherein the assemblies110 a, 110 b can be installed on the same or different semiconductorsubstrate processing apparatuses such as a vacuum chamber of a plasmaetching apparatus or a deposition apparatus. Preferably, in this manner,two or more fluid handling components are coated at the same time.

Methods of forming ALD or MLD barrier coatings allow coatings to growlayer-by-layer in a highly precise and controllable fashion. Therefore,the thickness of ALD or MLD barrier coatings formed on the interiorfluid wetted surfaces of the fluid handling components can be tailoredas needed and applied conformally and uniformly over the interior fluidwetted surfaces of the fluid handling component, consequentlyeliminating the risks of undesired modification of part dimensions ofcomponents making up the fluid handling components, for example, such asan o-ring. Further, ALD and MLD processes can deposit pinhole freebarrier coatings, thus leading to complete coverage of the interiorfluid wetted surfaces of the fluid handling components. A variety ofinert materials, such as oxide/nitride/fluoride materials, can bedeposited by ALD processes with high coating adhesion on variousinterior fluid wetted surfaces such as metal surfaces, ceramic surfaces,or temperature-sensitive polymer surfaces of the fluid handlingcomponents. In a preferred embodiment, the ALD barrier coating is formedfrom Al₂O₃. In alternate embodiments, the ALD coating can include atleast one of tantalum (Ta), titanium (Ti), tungsten (W), zirconium (Zr),hafnium (Hf), molybdenum (Mo), niobium (Nb), vanadium (V), ruthenium(Ru) and/or chromium (Cr) and mixtures and/or alloys thereof. In analternate preferred embodiment, the MLD barrier coating is an organic,or an organic-inorganic hybrid material. For example, the MLD barriercoating can be a polyamide, a polyimide, a polyuria, a polythiourea, apolyurethane, a polyazomethine, or a polyester material. In a preferredembodiment, the ALD or MLD barrier coating has a thickness of about 0.1to 500 nm or greater, wherein the ALD or MLD barrier coating preferablyhas a thickness of about 10 nm or greater and more preferably about 100nm or greater.

In a preferred embodiment, only the interior fluid wetted surfaces ofthe fluid handling components will be coated. The interior fluid wettedsurfaces can be any interior surface of the fluid handling componentwherein the interior of the fluid handling component forms the processregion of the ALD or MLD apparatus. Preferably, vacuum seals included inthe fluid handling component (i.e. gaskets and O-rings) serve as hardmasks to prevent the coating of external surfaces (i.e. non fluid wettedsurfaces) of the fluid handling component. In certain embodiments,barrier coatings on the external surfaces of fluid handling componentscan lead to process errors, and therefore are preferably avoided. Forexample, ALD coatings of insulative material on gas weldment exteriorscould interfere with a RF grounding path of the weldment and possiblylead to light-up of process gas in the weldment.

FIGS. 3 and 4 each illustrate an exemplary fluid handling componentwhich can include the ALD or MLD barrier coating on interior fluidwetted surfaces thereof. FIG. 3 illustrates a cross section of a gas box110 wherein the interior of the gas box forms the process region of theALD or MLD apparatus and wherein the interior of the gas box forms theinterior fluid wetted surfaces 163 of the gas box which includes an ALDor MLD barrier coating 164 thereon. FIG. 4 illustrates a temperaturecontrolled top plate 110 which includes a coolant inlet port 105 and acoolant outlet port 115 for circulating the coolant (e.g. deionizedwater) through a passage thereof. The passage forms the interior of thefluid handling component wherein the interior fluid wetted surfaces 163of the passage includes the ALD or MLD barrier coating 164 thereon.

An operator can control the formation of the ALD or MLD barrier coatingthrough interaction with a system controller 200 such as a monitor and adata entry device such as the keyboard. The system controller 200 isemployed to control process conditions during deposition, postdeposition treatments, and/or other process operations. The controller200 will typically include one or more memory devices and one or moreprocessors. The processor may include a CPU or computer, analog and/ordigital input/output connections, stepper motor controller boards, etc.

In certain embodiments, the controller 200 controls all of theactivities of the ALD or MLD apparatus (i.e. coating system). The systemcontroller 200 executes system control software including sets ofinstructions for controlling the ALD or MLD barrier coating process,flow rates, exhaust rates, and temperatures of reactant and inert gasesand their relative mixing, temperature of the one or more heaters 150,pressure in the interior of the fluid handling component 110, and otherparameters of the coating process. Other computer programs stored onmemory devices associated with the controller may be employed in someembodiments.

Typically there will be a user interface associated with controller 200.The user interface may include a display screen, graphical softwaredisplays of the apparatus and/or process conditions, and user inputdevices such as pointing devices, keyboards, touch screens, microphones,etc.

A non-transitory computer machine-readable medium can comprise programinstructions for control of the ALD or MLD apparatus (i.e. coatingsystem). The computer program code for controlling the processingoperations can be written in any conventional computer readableprogramming language: for example, assembly language, C, C++, Pascal,Fortran or others. Compiled object code or script is executed by theprocessor to perform the tasks identified in the program.

Signals for monitoring the process may be provided by analog and/ordigital input connections of the system controller. The signals forcontrolling the process are output on the analog and digital outputconnections of the apparatus.

While the coating system and method of forming an ALD or MLD barriercoating on interior surfaces of a fluid handling component have beendescribed in detail with reference to specific embodiments thereof, itwill be apparent to those skilled in the art that various changes andmodifications can be made, and equivalents employed, without departingfrom the scope of the appended claims.

What is claimed is:
 1. A fluid handling component for a vacuum chamberof a semiconductor substrate processing apparatus, the fluid handlingcomponent comprising interior fluid wetted surfaces and an atomic layerdeposition (ALD) or molecular layer deposition (MLD) barrier coating onthe interior fluid wetted surfaces wherein the fluid wetted surfacesincluding the ALD or MLD barrier coating are configured to be contactedby a process gas and/or fluid during a semiconductor substrateprocessing process wherein the ALD or MLD barrier coating protects theunderlying fluid wetted surfaces from erosion and/or corrosion.
 2. Thefluid handling component of claim 1, wherein the fluid handlingcomponent is an exhaust assembly, a gas delivery system, a gas box, agas stick, a proximity head, an air filtering unit, a deionized watercirculation system, a facility line, a gas line, a gas distributionsystem including a gas switching section, a temperature controlled topplate, a temperature controlled base plate, and/or a diffuser of thevacuum chamber of the semiconductor substrate processing apparatus. 3.The fluid handling component of claim 1, wherein the ALD barrier coatingincludes tantalum (Ta), titanium (Ti), tungsten (W), zirconium (Zr),hafnium (Hf), molybdenum (Mo), niobium (Nb), vanadium (V), ruthenium(Ru) and/or chromium (Cr) and mixtures and/or alloys thereof.
 4. Thefluid handling component of claim 1, wherein the ALD barrier coating is:(a) an oxide, nitride, or fluoride material; and/or (b) aluminum oxide(Al₂O₃).
 5. The fluid handling component of claim 1, wherein the MLDbarrier coating is: (a) a polyamide, a polyimide, a polyuria, apolythiourea, a polyurethane, a polyazomethine, or a polyester material;and/or (b) an organic, or an organic-inorganic hybrid material.
 6. Thefluid handling component of claim 1 wherein thickness of the ALD or MLDbarrier coating is about 0.1 to 500 nm or greater.
 7. The fluid handlingcomponent of claim 1, wherein the interior fluid wetted surfacescomprises a plurality of parts that are pre-assembled and vacuum sealedbefore formation of the ALD or MLD barrier coating.
 8. The fluidhandling component of claim 7, the plurality of parts when pre-assembledis configured to form a process space for the ALD or MLD barriercoating.